The present invention relates to apparatus for generating an alarm sound and, more particularly, to apparatus for generating an alarm sound in which the generation of the alarm sound is controlled by electronic means.
Conventionally, many types of electronic alarm clocks have a crystal generator the output of which is divided to actuate the clock and provide a time representation and a suitable one of the divided outputs is further used for generating an alarm sound. These electronic clocks have circuits most of which are integrated. In these integrated circuits, interference by external noises is increases as the number of terminals is increased so as to cause failure or damage of the semiconductor device.
This problem is serious especially in a case where the clock is provided with various modes of alarm functions such as interruption of the alarm or the like, because the number of input terminals of the integrated circuit is increased as the number of switches provided corresponding to each of the aforementioned functions is increased.